Value of serum glycated albumin and high-sensitivity C-reactive protein levels in the prediction of presence of coronary artery disease in patients with type 2 diabetes

Variation in high-sensitivity C-reactive protein levels over 24 hours in patients with stable coronary artery disease

Limited, controversial data exist regarding changes in high-sensitivity C-reactive protein (hs-CRP) levels over short times and the importance of detecting these changes in patients who have coronary artery disease (CAD). We investigated the variation of hs-CRP levels and their association with the severity of CAD in patients with stable CAD.We measured morning, midday, evening, and midnight hs-CRP levels in 124 patients (94 with CAD, 30 with normal coronary arteries), who were evaluated via coronary angiography and Gensini scoring. Patients were divided into 3 groups (normal coronary arteries, mild CAD, or severe CAD) according to Gensini score.Temporal hs-CRP levels varied significantly--the highest mean concentrations were found in the morning, and the lowest concentrations at midday (P <0.001). All temporal hs-CRP measurements and the absolute increase in hs-CRP levels were significantly higher in patients with severe CAD (both P <0.001). The most significant predictors of CAD severity were age (P=0.005), midday hs-CRP level (P <0.001), and brain natriuretic peptide level (P=0.045). Receiver operating characteristic curve analysis showed that cutoff values of hs-CRP taken at different times predicted severe CAD with similar sensitivity and specificity. Different cutoff values for temporal hs-CRP levels correlated with the severity of CAD. Serum levels of hs-CRP varied over 24 hours, whether patients had CAD or normal coronary arteries.

Management of diabetes in dialysis patients

Diabetes mellitus is the most common cause of kidney disease worldwide, and of end-stage renal disease (ESRD) in the United States and elsewhere. Mortality rates of patients with diabetes mellitus (DM) on chronic dialysis exceed those of non-DM patients. ESRD and dialysis add to the complexity of glycemic management in this population. Abnormal glucoregulation includes reduced insulin sensitivity and renal clearance of the hormone. Implementation of dialysis affects glucose and insulin levels, while increasing insulin sensitivity. Tight glycemic control carries an increased risk of hypoglycemia in ESRD. Monitoring glycemic control with hemoglobin A(1c) (HbA(1c)) levels may be suboptimal because of analytical and clinical variability of the test. Recent studies on HbA(1c) and clinical outcomes in this population present complementary results on the role of glycemic control in patients with DM with ESRD.

Glycated albumin and direct low density lipoprotein cholesterol levels in type 2 diabetes mellitus

BACKGROUND

Diabetes mellitus is a major risk factor for coronary heart disease (CHD), renal failure, retinopathy, and neuropathy. Lowering glycosylated hemoglobin (HbA1c) as well as low-density lipoprotein-cholesterol (LDL-C) has been associated with a decreased risk of these complications. We evaluated the utility of glycated albumin (GA) and direct LDL-C, 2 novel assay, as compared to HbA1c and calculated LDL-C, in evaluating diabetes control and lipid in a heterogeneous population and in specific subgroups of patients with type 2 diabetes mellitus.

METHODS

We obtained fasting blood samples and measured HbA1c, GA, and direct LDL-C, as well as other parameters, in a multi-ethnic population of 616 male and female patients with type 2 diabetes and 895 non-diabetic controls.

RESULTS

HbA1c and GA levels, which measure different periods of glycemia, had a correlation of r=0.70 (p<0.001), and mean values in patients were 38.7% and 43.4% higher, respectively, than controls in men, and 41.1% and 40.1% higher, respectively, than controls, in women (both p<0.001). Calculated and direct LDL-C values correlated very highly (r=0.96, p<0.001). The correlations between HbA1c and GA, and between calculated and direct LDL-C were similar for subgroups defined by gender, race, age, and other factors.

CONCLUSIONS

Calculated LDL-C provides an accurate assessment of fasting LDL-C compared with a direct measurement in most subjects, except for those with hypertriglyceridemia, and GA correlates with HbA1c in diabetic and non-diabetic subjects and may serve as a reasonable marker of short term diabetic control.

Predictive value of the decrease in circulating dendritic cell precursors in stable coronary artery disease

DCs (dendritic cells) are present in atherosclerotic lesions leading to vascular inflammation, and the number of vascular DCs increases during atherosclerosis. Previously, we have shown that the levels of circulating DCPs (DC precursors) are reduced in acute coronary syndromes through vascular recruitment. In the present study, we have investigated whether DCP levels are also reduced in stable CAD (coronary artery disease). The levels of circulating mDCPs (myeloid DCPs), pDCPs (plasmacytoid DCPs) and tDCP (total DCPs) were investigated using flow cytometry in 290 patients with suspected stable CAD. A coronary angiogram was used to evaluate a CAD score for each patient as follows: (i) CAD excluded (n=57); (ii) early CAD (n=63); (iii) moderate CAD (n=85); and (iv) advanced CAD (n=85). Compared with controls, patients with advanced stable CAD had lower HDL (high-density lipoprotein)-cholesterol (P=0.03) and higher creatinine (P=0.003). In advanced CAD, a significant decrease in circulating mDCPs, pDCPs and tDCPs was observed (each P<0.001). A significant inverse correlation was observed between the CAD score and mDCPs, pDCPs or tDCPs (each P<0.001). Patients who required percutaneous coronary intervention or coronary artery bypass grafting had less circulating mDCPs, pDCPs and tDCPs than controls (each P<0.001). Multiple stepwise logistic regression analysis suggested mDCPs, pDCPs and tDCPs as independent predictors of CAD. In conclusion, we have shown that patients with stable CAD have significantly lower levels of circulating DCPs than healthy individuals. Their decrease appears to be an independent predictor of the presence of, and subsequent therapeutic procedure in, stable CAD.

Exercise training alters effect of high-fat feeding on the ACTH stress response in pigs

Eating and physical activity behaviors influence neuroendocrine output. The purpose of this study was to test, in an animal model of diet-induced cardiovascular disease, the effects of high-fat feeding and exercise training on hypothalamo-pituitary-adrenocortical (HPA) axis activity. We hypothesized that a high-fat diet would increase circulating free fatty acids (FFAs) and decrease the adrenocorticotropic hormone (ACTH) and cortisol response to an acute stressor. We also hypothesized that exercise training would reverse the high-fat diet-induced changes in FFAs and thereby restore the ACTH and cortisol response. Pigs were placed in 1 of 4 groups (normal diet, sedentary; normal diet, exercise training; high-fat diet, sedentary; high-fat diet, exercise training; n = 8/group). Animals were placed on their respective dietary and activity treatments for 16-20 weeks. After completion of the treatments animals were anesthetized and underwent surgical intubation. Blood samples were collected after surgery and the ACTH and cortisol response to surgery was determined and the circulating concentrations of FFAs, glucose, cholesterol, insulin, and IGF-1 were measured. Consistent with our hypothesis, high-fat feeding increased FFAs by 200% and decreased the ACTH stress response by 40%. In exercise-trained animals, the high-fat diet also increased FFA; however, the increase in FFA in exercise-trained pigs was accompanied by a 60% increase in the ACTH response. The divergent effect of high-fat feeding on ACTH response was not expected, as exercise training alone had no effect on the ACTH response. Results demonstrate a significant interaction between diet and exercise and their effect on the ACTH response. The divergent effects of high-fat diet could not be explained by changes in weight gain, blood glucose, insulin, or IGF-1, as these were altered by high-fat feeding, but unaffected by exercise training. Thus, the increase in FFA with high-fat feeding may explain the blunted ACTH response to an acute stressor in sedentary animals, but cannot explain the exaggerated response in exercise trained animals.

High-sensitivity C-reactive protein and silent myocardial ischemia in Chinese with type 2 diabetes mellitus

Coronary artery disease (CAD) is a major cause of morbidity and mortality in patients with type 2 diabetes mellitus. When diabetes exists in patients with established CAD, absolute risk for future events is very high. Diabetic patients often have severe, yet asymptomatic, CAD. Although high-sensitivity C-reactive protein (hsCRP) is a strong independent risk factor for cardiovascular events, there is an unclear association between it and silent myocardial ischemia in diabetic patients. In this study, we assess the relationship between hsCRP and silent myocardial ischemia in Chinese with type 2 diabetes mellitus. We designed a cross-sectional study with 225 asymptomatic diabetic patients having no known CAD. Ischemia was assessed by myocardial perfusion imaging. A total of 109 patients (48.4%) was found to have silent myocardial ischemia. Logistic regression analysis revealed age (odds ratio = 4.01, P = .002) (95% confidence interval, 1.98-7.44) and hsCRP (odds ratio = 2.58, P = .005) (95% confidence interval, 1.33-5.01) to be associated with greater risk of silent myocardial ischemia. Using the American Diabetes Association screening guidelines to evaluate risk, we found silent myocardial ischemia to be equally distributed between diabetic patients with 2 or more cardiac risk factors and those with less than 2 risk factors. Twenty-seven (24.8%) patients with silent myocardial ischemia were missed when the American Diabetes Association guidelines were used alone. High-sensitivity C-reactive protein was associated with silent myocardial ischemia in our study. High-sensitivity C-reactive protein might help detect silent myocardial ischemia in diabetic Chinese who may need aggressive treatment to reduce future CAD morbidity and mortality in Taiwan.

Carotid intima-media thickness and markers of inflammation, endothelial damage and hemostasis

BACKGROUND

Different soluble molecules involved in inflammation, endothelial damage, or hemostasis are recognized as potential cardiovascular risk markers. Studies to assess the role of these markers in the atherosclerotic process by evaluating their relationship to carotid intima-media thickness (C-IMT) tend to provide contrasting results.

PURPOSE

To perform a review of studies addressing the association between C-IMT and soluble markers and to investigate whether the observed inconsistencies could be explained by the characteristics of the patients included in different studies, for example prevalence of atherosclerotic disease (atherosclerotic burden), gender, age, or occurrence of specific vascular risk factors (VRFs).

DATA SOURCES

PubMed and Embase (January 1990 to March 2006).

STUDY SELECTION

Articles in English reporting original cross-sectional studies.

DATA EXTRACTION

Two authors independently extracted data on study design, population, sample size, ultrasonic methodology, and statistical approach.

DATA SYNTHESIS

Despite the marked heterogeneity of results presented in the literature, meta-analysis established that studies showing positive associations between C-IMT and plasma levels of C-reactive protein (CRP) or fibrinogen are in the majority. Funnel plot analyses suggested the absence of an important publication bias. Data on the relationships between C-IMT and other soluble markers are by contrast scanty, contradictory, or unconfirmed by multivariate (as opposed to univariate) analyses, and the freedom from publication bias here cannot be vouched for. The degree of atherosclerotic burden in the population studied does not account for the heterogeneity of findings reported. Gender, noninsulin-dependent diabetes mellitus (NIDDM) and hypercholesterolemia influence the association between C-IMT and CRP. Blood pressure and hypercholesterolemia influence the association between C-IMT and fibrinogen. For all the other soluble markers considered, the number of groups was too small for this kind of statistical considerations.

LIMITATIONS

Heterogeneity in ultrasound methodologies and in statistical approach limited comparability between studies. For most soluble markers, publication bias of positive results cannot be excluded.

CONCLUSIONS

Only CRP and fibrinogen seem to be unequivocally related to C-IMT. For all the other soluble markers considered, no clear-cut conclusions can be drawn.

Enhanced glycation of hemoglobin and plasma proteins is associated with increased lipid peroxide levels in non-diabetic hypertensive subjects

BACKGROUND

Accumulating evidences indicate that lipid peroxidation and protein glycation play a vital role in the pathogenesis of cardiovascular disease. The purpose of the present study was to evaluate the levels of lipid peroxides and glycated proteins in non-diabetic hypertensive patients and to assess the possible nexus between them, among these subjects.

METHODS

Thirty hypertensive patients and 25 normotensive subjects were enrolled in the present study. Lipid peroxides, glycated hemoglobin, and fructosamine levels were estimated in both groups.

RESULTS

Lipid peroxides, glycated hemoglobin, and fructosamine levels were significantly increased in hypertensive subjects in comparison with normotensive subjects. When partial correlation analysis was performed, malondialdehyde was significantly associated with glycated hemoglobin and fructosamine.

CONCLUSIONS

An increased glycation of proteins was found in non-diabetic hypertensive subjects. These data also support the premise that lipid peroxidation per se plays a role in glycation of hemoglobin and plasma proteins.

Neointimal hyperplasia persists at six months after sirolimus-eluting stent implantation in diabetic porcine

Background

Observational clinical studies have shown that patients with diabetes have less favorable results after percutaneous coronary intervention compared with the non-diabetic counterparts, but its mechanism remains unclear. The aim of this study was to examine the changes of neointimal hyperplasia after sirolimus-eluting stent (SES) implantation in a diabetic porcine model, and to evaluate the impact of aortic inflammation on this proliferative process.

Methods

Diabetic porcine model was created with an intravenous administration of a single dose of streptozotocin in 15 Chinese Guizhou minipigs (diabetic group); each of them received 2 SES (Firebird, Microport Co, China) implanted into 2 separated major epicardial coronary arteries. Fifteen non-diabetic minipigs with SES implantation served as controls (control group). At 6 months, the degree of neointimal hyperplasia was determined by repeat coronary angiography, intravascular ultrasound (IVUS) and histological examination. Tumor necrosis factor (TNF)-α protein level in the aortic intima was evaluated by Western blotting, and TNF-α, interleukin (IL)-1β and IL-6 mRNA levels were assayed by reverse transcription and polymerase chain reaction.

Results

The distribution of stented vessels, diameter of reference vessels, and post-procedural minimal lumen diameter were comparable between the two groups. At 6-month follow-up, the degree of in-stent restenosis (40.4 ± 24.0% vs. 20.2 ± 17.7%, p < 0.05), late lumen loss (0.33 ± 0.19 mm vs. 0.10 ± 0.09 mm, p < 0.001) by quantitative angiography, percentage of intimal hyperplasia in the stented area (26.7 ± 19.2% vs. 7.3 ± 6.1%, p < 0.001) by IVUS, and neointimal area (1.59 ± 0.76 mm² vs. 0.41 ± 0.18 mm², p < 0.05) by histological examination were significantly exacerbated in the diabetic group than those in the controls. Significant increases in TNF-α protein and TNF-α, IL-1β and IL-6 mRNA levels were observed in aortic intima in the diabetic group.

Conclusion

Neointimal hyperplasia persisted at least up to 6 months after SES implantation in diabetic porcine, which may be partly related to an exaggerated inflammatory response within the blood vessel wall. Our results provide theoretical support for potential direct beneficial effects of anti-diabetic and anti-inflammation medications in reducing the risk of restenosis after stenting.